Crash during a register access for PCIe compliance test

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
,
1

Hi,

We do PCIe compliance test by following Document “Jetson AGX Xavier Series Tuning and Compliance Guide DA-09855-001_v1.3” - Section “Jetson AGX Xavier PCIe Compliance Testing Reference” - Page 27.

When we tried to access the register “0x14160004” or “0x141A0004”
using devmem2 and busybox devmem tools
we get the following output from a remote terminal:

agx@ubuntu:~$ sudo devmem2 0x14160004
/dev/mem opened.
Memory mapped at address 0x7f9d299000.
Bus error

agx@ubuntu:~$ sudo busybox devmem 0x14160004
0xDEAD2003

MG: THE SYSTEM CRASHES AND RESTARTS HERE !!!

From a local terminal, the last register value print to the command-line is not visible.
There is a sudden freeze and than the crash/restart.

Our system with a custom baseboard with SDK 4.6.

But I got the same result from our AGX Xavier development kit with SDK 4.6.3 with the following logs (attached):
lspci.log (1.6 KB)
dmesg.log (73.7 KB)

How can we access those registers?

Best,
Mustafa Gueler

2

Let me add the log files also from our custom system:
dmesg.log (76.4 KB)
lspci.log (18.0 KB)

In this load, the PCIe power-down is disabled from the corresponding dtsi file.

Best,
Mustafa Gueler

4

Hi,
For information, do you use custom board or Xavier developer kit?

5

Hi,

We encountered the problem on our custom board with SDK 4.6.
Later, we tried the same with the AGX Xavier developer kit
without any modification to the original image from SDK 4.6.3.
The result was the same.

The problem occurs with PEX x1 register modification.
I assume there is some problem with 0x14160004.

For PEX x4 it seems working.
Its address is 0x141A0004.

Please see the page below:
Document “Jetson AGX Xavier Series Tuning and Compliance Guide DA-09855-001_v1.3” - Section “Jetson AGX Xavier PCIe Compliance Testing Reference” - Page 27.

Best,
Mustafa

8

0x14160000 is C4 and you didn’t enable it in your device tree at all. Devkit does not use it either, so crash on devkit is also expected.

10

Hi Wayne,

Thank you for the explanation. You are right.

We thought that it should be tested as we saw it in the compliance document.
It would be nice to emphasize there that they are only examples.

Is there any document that shows 0x14160000 - C4 and other relations?

Best,
Mustafa

11

If you are talking about the mapping. Then Orin document could be referred for Xavier case too.

image
image623×589 42.6 KB

Please only refer to those controllers that exist on Xavier AGX.

1 Like